Objectives: We investigated the association between multimorbidity among patients hospitalised with COVID-19 and their subsequent risk of mortality. We also explored the interaction between the presence of multimorbidity and the requirement for an individual to shield due to the presence of specific conditions and its association with mortality. Design: We created a cohort of patients hospitalised in Scotland due to COVID-19 during the first wave (between 28 February 2020 and 22 September 2020) of the pandemic. We identified the level of multimorbidity for the patient on admission and used logistic regression to analyse the association between multimorbidity and risk of mortality among patients hospitalised with COVID-19. Setting: Scotland, UK. Participants: Patients hospitalised due to COVID-19. Main outcome measures: Mortality as recorded on National Records of Scotland death certificate and being coded for COVID-19 on the death certificate or death within 28 days of a positive COVID-19 test. Results: Almost 58% of patients admitted to the hospital due to COVID-19 had multimorbidity. Adjusting for confounding factors of age, sex, social class and presence in the shielding group, multimorbidity was significantly associated with mortality (adjusted odds ratio 1.48, 95%CI 1.26–1.75). The presence of multimorbidity and presence in the shielding patients list were independently associated with mortality but there was no multiplicative effect of having both (adjusted odds ratio 0.91, 95%CI 0.64–1.29). Conclusions: Multimorbidity is an independent risk factor of mortality among individuals who were hospitalised due to COVID-19. Individuals with multimorbidity could be prioritised when making preventive policies, for example, by expanding shielding advice to this group and prioritising them for vaccination.
Bibliographical noteFunding Information:
The authors would like to thank the wider EAVE II team for their support for this study. The authors would also like to thank Helen R Stagg for her valuable comments. The authors would like to acknowledge the support of the eDRIS Team (Public Health Scotland) for their involvement in obtaining approvals, provisioning and linking data and the use of the secure analytical platform within the National Safe Heaven.
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: UA is funded by the HDR UK Measuring and Understanding Multi-morbidity using Routine Data in the UK – (MUrMuRUK) project. AF is funded by the CSO Rapid Research in Covid-19 Programme. EAVE II funded by the Medical Research Council (MR/R008345/1) with the support of BREATHE - The Health Data Research Hub for Respiratory Health [MC_PC_19004], which is funded through the UK Research and Innovation Industrial Strategy Challenge Fund and delivered through Health Data Research UK. Linkage of these datasets was funded via the Chief Scientist Office, Scotland.
Data Availability StatementAll the codes and figures will be made available on EAVE-II Github (https://github.com/EAVE-II/multimorbidity-and-mortality-hospital-admission)
- hospital admissions